Some of these things don't necessarily "need" to be skinned.  If you don't skin them, Windowblinds takes them from other places.  For instance, if you don't skin the Controls > Progress bars > Windows 7 taskbar, it will take the image from the flashing taskbar button and use that image as the progress bar in taskbar.  And as jazzymyr said, if you don't skin the Show desktop button, when you mouse over where the place where the button is, the Windows7 image shows up and the desktop is shown.

If I were not a skinner, I wouldn't know half of what my operating system does.  I was just starting to learn all the Vista parts when my upgrade for Win7 came in the mail; there's lots to learn about the cool new features.  I'm tearing apart a lot of other blinds to figure things out. 

Tooltips is that popup box that shows up when you install a new WB skin that says "A new skin has been installed....click here if you want to apply this skin" and things like the "safely remove hardware" popup box, if you plug in something like a USB flash drive and want to safely remove it.  It's that little information popup area over the tray expander.

This may help some:

If you go to the tools menu and choose preferences, then go to the advanced tab, you'll see at the bottom of the dialog box an option to choose your "Operating System to target." You can choose between xp, vista, 7, o "all os's".

I always keep it on "all," but it may benefit you some to choose an os at a time.

Now, just a disclaimer; doing this will allow you to edit all parts that that os needs, and of course we know that many of those parts overlap between os's.

FYI: The tooltip is also visible in Vista! When you mouseover the time on the taskbar you will see it. It does not show the tooltip arrow, but you will see the 'box'.

wow windows 7 wasnt that hard to skin once i got my head around the few extra bits...had fun with that tooltip arrow. i thought it was an 'actual' arrow and coloured it black....lol then when i went back into w7 i realized it was part of the tool tip window...so then changed it back to match the tool tip colours.........silly me....

also had to change the background colours of my treenode...looked like crap when i moused over them in w7 and the background is white and the treenode background was cream BLAH. gave a nice horrible square outline...

i actually learnt alot from the diamond skin.......as i did via learning to skin vista... all good so far.

the only bummer was i had to make square taskbar buttons instead of round edged ones to it supports the double height of the w7 task bar if people choose to use that option.

**edit* now all i gotta do is wait for an upload solution since i cant upload atm..***

want the best and even if you still need help with any of it send me mail or just ask here or on irc... but here is some really good stuff too http://danillooc.deviantart.com/

look at the tuts they are very into it or if you have problems with 7 let me know. Be glad to help!!